/* ============ THEME VARIABLES ============ */
:root {
  --bg: #ffffff;
  --bg-secondary: #f7f6f3;
  --text: #1a1a1a;
  --text-muted: #6b6b6b;
  --border: #e5e2dc;
  --accent: #1f5c4a;
  --accent-hover: #16463a;
  --card-bg: #ffffff;
  --shadow: 0 2px 12px rgba(0,0,0,0.06);
  --font-serif: 'Georgia', 'Lora', serif;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
}

html.dark-mode {
  --bg: #14161a;
  --bg-secondary: #1c1f24;
  --text: #eaeaea;
  --text-muted: #9a9a9a;
  --border: #2c2f36;
  --accent: #3fae8c;
  --accent-hover: #55c9a4;
  --card-bg: #1c1f24;
  --shadow: 0 2px 12px rgba(0,0,0,0.4);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  transition: background 0.2s ease, color 0.2s ease;
  line-height: 1.6;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }

/* ============ HEADER ============ */
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
}
.logo { font-weight: 700; font-size: 1.2rem; color: var(--text); }
.main-nav { display: flex; align-items: center; gap: 24px; }
.main-nav a { color: var(--text); font-size: 0.95rem; }
.nav-cta {
  background: var(--accent);
  color: #fff !important;
  padding: 8px 16px;
  border-radius: 6px;
}
.nav-cta:hover { background: var(--accent-hover); }
.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 20px;
  width: 40px;
  height: 24px;
  cursor: pointer;
  position: relative;
  color: var(--text);
}
.icon-sun, .icon-moon { position: absolute; top: 50%; transform: translateY(-50%); font-size: 12px; }
.icon-sun { left: 5px; }
.icon-moon { right: 5px; display: none; }
html.dark-mode .icon-sun { display: none; }
html.dark-mode .icon-moon { display: inline; }
.mobile-nav-toggle { display: none; background: none; border: none; font-size: 1.5rem; color: var(--text); cursor: pointer; }

@media (max-width: 768px) {
  .main-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 24px;
    border-bottom: 1px solid var(--border);
    gap: 16px;
  }
  .main-nav.open { display: flex; }
  .mobile-nav-toggle { display: block; }
}

/* ============ FOOTER ============ */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 80px;
  padding: 32px 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.footer-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; }

/* ============ HERO / LANDING ============ */
.hero {
  padding: 80px 0 40px;
  text-align: center;
}
.hero h1 { font-size: 2.4rem; margin-bottom: 12px; }
.hero p { color: var(--text-muted); font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

/* ============ BOOK GRID ============ */
.book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 32px;
  padding: 40px 0 80px;
}
.book-card {
  background: var(--card-bg);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease;
}
.book-card:hover { transform: translateY(-4px); }
.book-card img { width: 100%; aspect-ratio: 2/3; object-fit: cover; display: block; background: var(--bg-secondary); }
.book-card-body { padding: 16px; }
.book-card-body h3 { margin: 0 0 4px; font-size: 1.05rem; }
.book-card-body p { margin: 0; color: var(--text-muted); font-size: 0.9rem; }
.book-card-price { margin-top: 8px; font-weight: 600; color: var(--accent); }

/* ============ BOOK DETAIL PAGE ============ */
.book-detail {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 48px;
  padding: 60px 0;
}
.book-detail img { width: 100%; border-radius: 10px; box-shadow: var(--shadow); }
.book-detail h1 { font-size: 2rem; margin-bottom: 4px; }
.book-detail .subtitle { color: var(--text-muted); font-size: 1.1rem; margin-bottom: 20px; }
.book-detail .price-box {
  background: var(--bg-secondary);
  border-radius: 10px;
  padding: 24px;
  margin: 24px 0;
}
.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 12px 24px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 600;
  text-align: center;
}
.btn:hover { background: var(--accent-hover); color: #fff; }
.btn-secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.btn-secondary:hover { background: var(--bg-secondary); color: var(--accent-hover); }

@media (max-width: 768px) {
  .book-detail { grid-template-columns: 1fr; }
  .book-detail img { max-width: 240px; margin: 0 auto; }
}

/* ============ AUTH FORMS ============ */
.auth-form {
  max-width: 400px;
  margin: 80px auto;
  background: var(--card-bg);
  padding: 40px;
  border-radius: 10px;
  box-shadow: var(--shadow);
}
.auth-form h2 { margin-top: 0; }
.auth-form label { display: block; margin: 16px 0 6px; font-size: 0.9rem; font-weight: 600; }
.auth-form input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font-size: 1rem;
}
.auth-form button { width: 100%; margin-top: 24px; }
.form-error { background: #fdecea; color: #b3261e; padding: 10px 14px; border-radius: 6px; margin-bottom: 16px; font-size: 0.9rem; }
html.dark-mode .form-error { background: #3a1f1e; color: #ff8a80; }

/* ============ LIBRARY ============ */
.library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 24px;
  padding: 40px 0 80px;
}

/* ============ READER ============ */
.reader-toolbar {
  position: sticky;
  top: 65px;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  z-index: 90;
  padding: 12px 0;
}
.reader-toolbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.reader-chapter-label {
  font-weight: 600;
  font-size: 0.95rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.font-controls { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.font-controls button {
  width: 32px; height: 32px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  border-radius: 6px;
  cursor: pointer;
  font-size: 1rem;
}
.reader-content {
  max-width: 700px;
  margin: 0 auto;
  padding: 40px 24px 120px;
  font-family: var(--font-serif);
}
.reader-content .chapter-block { margin-bottom: 80px; scroll-margin-top: 130px; }
.reader-content h2 { font-size: 1.8rem; margin-bottom: 4px; }
.reader-content h3.subtitle { font-weight: normal; font-style: italic; color: var(--text-muted); margin-top: 0; }
.reader-content h4 { font-size: 1.1rem; margin-top: 32px; }
.reader-content p { margin-bottom: 20px; }
.summary-box {
  font-style: italic;
  border-top: 1px solid var(--border);
  padding-top: 16px;
  margin-top: 32px;
  color: var(--text-muted);
}

.chapter-locked {
  position: relative;
  padding: 40px 24px;
  text-align: center;
  border: 1px dashed var(--border);
  border-radius: 10px;
  margin-bottom: 80px;
}
.chapter-locked-blur {
  filter: blur(5px);
  user-select: none;
  pointer-events: none;
  max-height: 200px;
  overflow: hidden;
}
.chapter-locked-overlay {
  margin-top: 20px;
}

/* Font size classes applied to .reader-content by JS */
.font-size-1 { font-size: 15px; }
.font-size-2 { font-size: 17px; }
.font-size-3 { font-size: 19px; }
.font-size-4 { font-size: 21px; }
.font-size-5 { font-size: 23px; }